A roof device for vehicle disclosed in JP2004299477A includes a movable panel to open or close an opening portion provided at a vehicle roof, two guide rails each of which are provided at a side in width direction of the opening portion and extending in longitudinal direction of the vehicle, operation mechanisms guided by the guide rail and supporting the movable panel. Further, a toothed belt is connected to each of the operation mechanism meshing with a driving gear rotated by a power source provided at a central portion of a front housing. The toothed belt, which is deformable in three-dimensional directions, is movably housed in a casing supported by the front housing. The casing is formed in a tubular shape having a rectangular cross section, which is formed so as to correspond to a shape of the toothed belt. In this configuration, when the toothed belt is moved by use of a drive of the driving gear in order to transmit the driving force to the operation mechanism, because the toothed belt is moved by forming a moving path with a guide by the casing, the toothed belt may not deflect to an unexpected level.
Thus, because the casing formed in the tubular shape having the rectangular cross section is formed independently from the front housing, the casing needs to be formed with a connecting portion at which the front housing or the guide rail is fixed. Accordingly, the number of the parts consisting the roof device is increased, and manufacturing hours may also be increased because of the fixing operation between the casing and the front housing and the like at the connecting portion. Further, because the casing is formed in the tubular shape having the rectangular cross section, the casing needs to be bent so as not to exceed a certain level in order to smoothly move the toothed belt, a level of flexibility of a setting of the moving path of the toothed belt may be decreased.
Furthermore, in consideration of a deformation of the casing in its longitudinal direction, the connecting portion of the casing may be formed in a sufficient length in order to compensate the deformation.
A need thus exists for a belt supporting apparatus for a vehicle roof and a roof device for a vehicle, which are not susceptible to the drawback mentioned above.